1. Field of the Invention
The present invention relates in general to the field of information handling system diagnostics, and more particularly to a system and method for information handling system clock source insitu diagnostics.
2. Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems are rapidly increasing in system hardware complexity, which can overwhelm field diagnostic review of a complete system when trying to determine a failure mechanism. As a result, information handling systems are often returned to the manufacturer even where a failure is repairable on site because the diagnosis of the failure is too complex. The return of repairable systems increases manufacturer warranty costs and negatively impacts the end user experience. However the performance of more advanced test techniques insitu to clearly identify failures and what is operating correctly are not practicable since such tests typically require external probes and or fixtures that are generally not available in the field. Two domains that are central to proper diagnosis of system failure are the power domain and the clocking domain. Information handling systems typically integrate a clock source, such as a Ck410 integrated clock controller, which allows for several features and clock domains. The accuracy of the oscillator input to a clock controller and the accuracy of the clock output are not readily confirmed at a system level or through peripheral devices. Instead, a failing system, device or port is known without an insitu way to isolate the failure to the clock. Indeed, discrete elements that use a clock source to implement clock trees are unbounded to conventional diagnostics with a probe approach. On die testing of a clock source is questionable since the power and clock failures cannot be determined from run time execution faults.
In addition to excessive complexity, conventional clock diagnostics also generally are expensive to implement. For instance, the Joint Test Action Group (JTAG) standard requires the use of an independent clock source and protocol with an associated high cost impact. Another conventional technique uses a counter for counting of a clock input, such as with a flip/flop, however, counting input provides only a narrow view of clock operations. Phase lock is used for PHY and PLL tracking within Verilog and Link status, however, phase lock for clock diagnostics fails to test the usage of clock data in a larger sense. Status indicators track clock operation, however, the power and clock status are generally are not readily available for insitu diagnostics since they require each other. Typically, for instance, information regarding the operation of a clock controller cannot be communicated through a management bus, such as the SMBus, unless the clock is operational. Thus, if diagnostics are required for a “hung” chip, system level management buses are generally not a reliable medium for communication of diagnostics information.